Update December 2010

Jet Grout Containment Barrier Completed!
Focus Shifts to Operable Unit 2

Operable Unit 1 (40 Willow Avenue)

OU-1 Operations, Maintenance and Monitoring Activities Continue
OU-2 Design Activities Underway
Operable Unit 1 (40 Willow Avenue)

Field activities to study the potential for removing Dense Non-Aqueous Phase Liquid (DNAPL) from within the barrier initiated in December 2009 continued through 2010.  Pilot wells to evaluate NAPL recoverability were placed within the holder foundation and inside of the barrier/containment cell.  A short-term recoverability test has been completed and National Grid is currently evaluating long-term NAPL recoverability. Operations and maintenance (O&M) activities commenced in October 2010 with the installation of three additional shallow recovery wells and O&M pumping of the containment cell.
On-going activities:

  • Continued O&M measures on the cap (maintenance and inspection) to ensure it continues to function as intended.

Recently Completed Activities:

  • Conducted general housekeeping activities at the Site in December.
  • Installed three additional shallow recovery wells within the containment cell.
  • Developed (pumped) newly installed recovery wells to remove sediment.
  • Completed O&M pumping of recovery wells.
  • Surveyed the newly installed recovery wells.
  • Collected ground water level measurements at wells throughout OU-1 and vicinity.
  • Issued the Final Ground Water Interim Remedial Measure (IRM) Work Plan for a small portion of a private property adjacent to OU-1.  New York State Department of Environmental Conservation (NYSDEC) and New York State Department of Health (NYSDOH) approved the Plan in December.
  • Obtained approval from NYSDEC and NYSDOH for the Final OU-1 Construction Completion Report (CCR).

Future near-term activities:

  • Continue maintenance and inspection of the OU-1 containment cell concrete cap.
  • Continue the collection of water level measurements from monitoring wells throughout OU-1 and vicinity.
  • Continue the evaluation of data from the non-aqueous phase liquid (NAPL) recovery pilot test.
  • Initiate the development of an O&M Plan for OU-1.
  • Implement the NYSDEC/NYSDOH-approved IRM Work Plan to increase dissolved oxygen levels within a small portion of the private property and enhance natural degradation of compound concentrations in groundwater.

Operable Unit 2 (25 Willow Avenue)

With the completion of the OU-1 barrier installation, focus has shifted to remedial design activities for OU-2.  OU-2 is the site of the former manufactured gas plant that previously operated at 25 Willow Avenue and was closed in 1957.  There are also two off-site areas located adjacent to the OU-2 Site at 89 Willow Avenue and across Bay Street at 1 Edgewater Street.  The remedial design activities have progressed with the approval of the final Remedial Design Work Plan and the 60% Design plans and specifications by NYSDEC and NYSDOH.
On-going activities:

  • Continue OU-2 remedial design activities.

Recently completed activities:

  • Presented the 60% Design plans and specification to NYSDEC and NYSDOH.  The 60% design was approved by NYSDEC and NYSDOH.
  • Installed temporary piezometers and collected ground water samples as part of the PDI.
  • Installed a fence around the adjacent 89 Willow Avenue property.

Future near-term activities:

  • Complete and submit the OU-2 90% Design for approval from NYSDEC and NYSDOH.
  • Complete supplemental remedial investigation activities within the Front Street right-of-way adjacent to 1 Edgewater Street and 89 Willow Avenue.
  • Complete a survey of the shoreline area adjacent to 1 Edgewater Street.
  • Conduct lead, asbestos, and PCB surveys in the existing warehouse building.

Community Air Monitoring Plan Summary
Operable Unit 1 (40 Willow Avenue)
A Community Air Monitoring Plan (CAMP) is implemented when intrusive activities are performed at Operable Unit 1.  There were no exceedances of the CAMP levels during the installation of the three recovery wells at OU-1 in October.  There were no intrusive activities at OU-1 during the months of November and December that required CAMP monitoring. Copies of previous weekly CAMP reports and other site documents for OU-1 are stored at the two public document repositories for the project.

Operable Unit 2 (25 Willow Avenue)
A Community Air Monitoring Plan (CAMP) is implemented in support of the PDI activities at the OU-2 properties during intrusive work .  The CAMP consists of portable monitors placed upwind and downwind of work areas.  There were no exceedences of the CAMP levels during the installation of the temporary piezometers at OU-2 in November.

Community Board 1
One Edgewater Plaza
Room 311
Staten Island, NY 10305
Phone #: (718) 981-6900
Borough President’s Office
Borough Hall
Staten Island, New York 10301
Phone #: (718) 816-2057

If you have any questions or comments about the work on the site, please use the site's Telephone Hotline at 718-982-7349.